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Results of the Weathering Group Vala Ragnarsdottir
SoilCritZone Partnes • Europe • Vala Ragnasdottir, Bristol UK - Co-ordinator • Nikos Nikolaidis, Chania, Greece • Steve (Barney) Banwart, Sheffield, UK • Jerome Gaillardet, Paris, France • Martin Novak, Prague, Czech Republic • Paulina van Gaans, Utrecht, Netherlands • Svetla Rousseva, Sofia, Bulgaria • Winfried Blum, Vienna, Austria • Par Aagard, Oslo, Norway • USA • Susan Brantley and Tim White, PennState, USA http://sustainability.gly.bris.ac.uk/soilcritzone
Resource depletion… We now are a geological force - • move 10x more material per year than nature! • In 30 years • Have used up 1/3 of world’s resources • 1/3 of our forests • ¼ of our most productive soils … every year 24 billion tonnes are eroded off our land
Study of life-cycle of soils for sustainability • Soil the most important resource after water • With soils eroding faster than they are being formed - we are living unsustainably • Earth habitants 6.7 billion and rising • If we loose our soils, we will not be able to feed the Earth population
Ronald Wright (A Short History of Progress): empires that collapse show similar behaviour Stick to entrenched belief and practices, robbing the future to pay the present Spend the last reserves of natural capital on reckless binge of excessive wealth and glory … does this sound familiar????
Past civilization collapses • Localized, e.g. the world’s first civilisation – the Sumer from Southern Mesopotamia, which is now Iraq – collapsed around 2000 BC as a result of soil degradation • With 6.7 billion people and rising the collapse is more likely to be Global...
Is this you? Problems arise when people loose sightof the “big picture”
The mycorrhiza weathering engine (After Landeweert et al., 2001) Nutrients Organic Carbon H+ H+ H+ Organic acids Siderophores Intimate contact with minerals High-affinity selective ion uptake Tolerance of high acidity and Al3+ions
Time for formation versus erosion • Life cycle analysis of soil has been ignored • Soil science very fragmented • Soil formation 50 to 1000 years for A and B horizons • In extreme conditions - 10,000 years • Agronomists quote 1 t/ha/yr – 7 mm/100 yrs • Slow! - of the order of <1-10 mm/100 yrs • Soil erosion a major problem today • Fast! - of the order of 100 - 1000 mm/100 yrs • Considered to be as serious an environmental problem as global warming!
Our thought process Linear but need to change to.. Cyclic
Weathering and soil formation • Research questions – what parameters needed • How to determine dominant factors controlling chemical weathering and quantify them in a given environment and at various scales • How physical, chemical, and biological weathering processes are coupled, and how can these couplings can be elucidated and quantified • How to advance our ability to predict weathering processes over the range of pertinent spatial scales, including mineral surfaces, laboratory reactors, soil profiles, catchments, and global systems
Pedological and hydrological scales Lin et al. (2006)